Guzzetta Fabrizio, Roig Anna, Julián-López Beatriz
Institute of Advanced Materials (INAM), Universitat Jaume I , Av. Sos Baynat s/n, 12071 Castellón, Spain.
Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus de la UAB , 08193 Bellaterra, Spain.
J Phys Chem Lett. 2017 Dec 7;8(23):5730-5735. doi: 10.1021/acs.jpclett.7b02473. Epub 2017 Nov 13.
An ultrafast route to prepare up-converting single β-phase NaYF:Yb,Ln (Ln: Er, Tm, or Tb) short nanorods (UCNRs) of high quality was developed. This new procedure affords reactive-surface nanorods that are easily coated by direct injection of suitable capping ligands. Thus highly crystalline nanorods with excellent UC fluorescence and good solvent-selective dispersion are obtained, which represents a significant advance in the field and enlarges their use for biomedical and other technological applications. Unlike other methodologies, the short reaction time provides a kinetic control over crystallization processes, and the β-phase and rod morphology is preserved regardless of the optically active Ln ion. The UC emission was finely tuned by using the most popular Yb/Tm and Yb/Er pairs. More importantly, UCNRs doped with the unusual Yb/Tb pair, with no ladder-like energy levels, provided a nice emission upon near-infrared excitation, which constitutes the first example of phonon-assisted cooperative sensitization to date in pure β-NaYF nanocrystals.
开发了一种超快制备高质量上转换单β相NaYF:Yb,Ln（Ln: Er、Tm或Tb）短纳米棒（UCNRs）的方法。这一新工艺可提供具有反应性表面的纳米棒，通过直接注入合适的封端配体可轻松对其进行包覆。由此获得了具有优异上转换荧光和良好溶剂选择性分散性的高度结晶纳米棒，这代表了该领域的一项重大进展，并扩大了它们在生物医学和其他技术应用中的用途。与其他方法不同，短反应时间对结晶过程提供了动力学控制，并且无论光学活性Ln离子如何，β相和棒状形态均得以保留。通过使用最常用的Yb/Tm和Yb/Er对，对上转换发射进行了精细调节。更重要的是，掺杂不寻常的Yb/Tb对且没有阶梯状能级的UCNRs在近红外激发下产生了良好的发射，这是迄今为止纯β-NaYF纳米晶体中声子辅助协同敏化的首个例子。
